Biomedical subjects

Fumiyuki Goto

Publications and source records attributed to Fumiyuki Goto.

15 recordsLinked to original sources

PubMed2006

Cadmium inducible Fe deficiency responses observed from macro and molecular views in tobacco plants.

Responses induced by Cd exposure were assessed in tobacco seedlings (Nicotiana tabacum L.) using macro and molecular indices. The 100 microM of Cd exposure reduced the total dry weight and chlorophyll index of the seedlings as much as the genuine Fe-deficiency. Concentration of Fe in the shoots decreased, whereas that in the roots increased by the Cd exposure, especially in the apoplasmic space. It is probable that Cd interferes mainly with the step of Fe-translocation from the roots to shoots and this sets the upper-part of the plant in a state of Fe-deficiency. The Cd exposure coordinately increased the expressions of the exogenous and the endogenous Fe-deficiency responsive genes, HvIDS2(pro)::GUS, NtFRO1 and NtIRT1 in the roots. This is the first data to demonstrate the responses of Cd-inducible Fe-deficiency at a molecular level.

Cadmium↗

PubMed2005

Iron accumulation does not parallel the high expression level of ferritin in transgenic rice seeds.

To answer the question whether iron accumulation in transgenic rice seeds depends on the expression level of exogenous soybean ferritin, we generated two kinds of ferritin hyper-expressing rice lines by introducing soybean ferritin SoyferH-1 gene under the control of the rice seed storage glutelin gene promoter, GluB-1 and the rice seed storage globulin gene promoter, Glb-1, (GluB-1/SoyferH-1 and Glb-1/SoyferH-1, DF lines), and by introducing the SoyferH-1 gene under the control of Glb-1 promoter alone (Glb-1/SoyferH-1, OF lines). Ferritin expression was restricted to the endosperm in both lines and protein levels determined by western blot analysis were up to 13-fold higher than in a construct previously reported FK22 (GluB-1/SoyferH-1, in genetically Kitaake background); [corrected] however, the maximum iron concentrations in seeds of both of the new lines were only about 30% higher than FK22. The maximum iron concentration in the OF and DF lines was about threefold higher than in the non-transformant. The mean Fe concentration in leaves of ferritin over-expressing lines decreased to less than half of the non-transformant while that the plant biomasses and seed yields of the ferritin-transformed lines were not significantly different from those of the non-transformant, suggesting that accumulation of Fe in seeds of hyper-expression ferritin rice did not always depend on the expression level of exogenous ferritin but may have been limited by Fe uptake and transport. No obvious differences were observed for other divalent-metal concentrations (Ca, Cd, Cu, Mg, Mn and Zn) in the seeds among all experimental lines and non-transformant.

Ferritins↗

PubMed2005

[A case of fibromyalgia treated with medical and autogenic training].

Fibromyalgia, which is relatively rare, may include symptoms of dizziness, vertigo and tinnitus. Subject was 38 years old woman reporting vertigo and whole body pain. Cochleovestibular function was normal. Pain was gradually intensified during her outpatient clinic and she was admitted. Treatments including intramusclular injection of botulinus toxin and intravenous injection of steroid were applied. Psychological counseling and autogenic training were effective in relieving her pain and vertigo. During her admission, several spells of vertigo occurred but no nystagmus was found. The abnormality in proprioception and neural disintegration may be related to vertigo. Treatment should start as early as possible together with psychological therapy.

Adult↗

PubMed2005

[Two cases of Meniere's disease with drop attacks].

Drop attacks are sudden falls without concurrent vertigo whose etiology may be unknown. Drop attacks are also associated with cardiac, cerebrovascular, psychogenic, and vestibular disorders, in addition to seizures. Vestibular-based drop attacks without loss of consciousness can occur in patients with Meniere's disease. We present 2 cases of drop attack in patients with Meniere's disease. Case 1, a 65-year-old man, experienced 4 such attacks and case 2, a 55-year-old woman, experienced 20 within 2 years of Meniere's disease onset. Case 1 enjoyed spontaneous remission. In case 2, selective serotonin reuptake inhibitor (SSRI) administration suppressed attack frequency. Anxiety may predispose individuals to drop attack. Etiologically, inadequate stimulation of otolith organs may induce a sudden vestibulo spinal reflex that, in turn, causes sudden falls. To correctly diagnose drop attacks, the patient must exhibit sudden falls, and transient ischemic attack should be carefully ruled out.

Accidental Falls↗

PubMed2004

Induction of callus from a metal hypertolerant fern, Athyrium yokoscense, and evaluation of its cadmium tolerance and accumulation capacity.

The callus of a metal hypertolerant fern, Athyrium yokoscense, was induced from the spores generated on a small sectioned frond in vitro. The callus grew vigorously with the periodical medium change, especially in a liquid culture. When the callus and regenerated tissues were exposed to Cd, every tissue tolerated at least 1 mM Cd for >1 month. These tissues accumulated high levels of Cd (maximum 3.3 mg g(-1) dry weight in roots) in accordance with the Cd concentration of the medium, and the Cd concentrations of all parts, except roots, were at a similar level. The data suggest that the Cd tolerance of this fern is basically independent of the plant parts and the developmental stages, although the accumulation ability is higher in roots than in the other plant parts.

Cadmium↗

PubMed2004

Eye movements evoked by selective saccular nerve stimulation in cats.

OBJECTIVE: Because of technical obstacles in controlling current spread to adjacent peripheral nerve, eye movements evoked by activation of the otolith organs have not been investigated in detail compared to eye movements evoked by activation of the canal organs. We attempted to solve this problem by applying more sensitive methods using fine needle and strictly controlling stimulus current intensity compare with filed potential for selective stimulation. METHODS: Eye movements evoked by selective, unilateral saccular (SAC) nerve stimulation were investigated using both electrooculography (EOG) and video recording in decerebrated cats in the presence or absence of anesthesia. Electrical stimulation was applied to the SAC nerve through implanted acupuncture needles. RESULTS: In the absence of anesthesia and with stimulus intensities less than (3.1 +/- 2.7) x N(1)T, we found supraduction in both eyes or in either the ipsilateral or contralateral eye of different cats. We observed downward eye movements using a stronger stimulus intensity ((6.2 +/- 2.9)) x N(1)T). The threshold for downward eye movements was significantly greater than that for upward eye movements (P < 0.05). In anesthetized cats, only downward eye movements were observed when stimulus intensities less than 10 x N(1)T ((7.8 +/- 2.3) x N(1)T) were used. CONCLUSION: These results confirm the known sacculo-ocular anatomical connections, which are involved predominantly in vertical eye movements. Because the sacculo-ocular connections are relatively weak, the normal supraduction evoked by SAC activation can be easily modified by factors such as level of anesthesia and the method of stimulation.

Animals↗

PubMed2003

Differential spatial organization of otolith signals in frog vestibular nuclei.

Activation maps of pre- and postsynaptic field potential components evoked by separate electrical stimulation of utricular, lagenar, and saccular nerve branches in the isolated frog hindbrain were recorded within a stereotactic outline of the vestibular nuclei. Utricular and lagenar nerve-evoked activation maps overlapped strongly in the lateral and descending vestibular nuclei, whereas lagenar amplitudes were greater in the superior vestibular nucleus. In contrast, the saccular nerve-evoked activation map coincided largely with the dorsal nucleus and the adjacent dorsal part of the lateral vestibular nucleus, corroborating a major auditory and lesser vestibular function of the frog saccule. The stereotactic position of individual second-order otolith neurons matched the distribution of the corresponding otolith nerve-evoked activation maps. Furthermore, particular types of second-order utricular and lagenar neurons were clustered with particular types of second-order canal neurons in a topology that anatomically mirrored the preferred convergence pattern of afferent otolith and canal signals in second-order vestibular neurons. Similarities in the spatial organization of functionally equivalent types of second-order otolith and canal neurons between frog and other vertebrates indicated conservation of a common topographical organization principle. However, the absence of a precise afferent sensory topography combined with the presence of spatially segregated groups of particular second-order vestibular neurons suggests that the vestibular circuitry is organized as a premotor map rather than an organotypical sensory map. Moreover, the conserved segmental location of individual vestibular neuronal phenotypes shows linkage of individual components of vestibulomotor pathways with the underlying genetically specified rhombomeric framework.

Action Potentials↗

PubMed2003

Crystallization and preliminary X-ray crystallographic analysis of plant ferritin from Glycine max.

The iron storage protein ferritin from soybean (Glycine max) was expressed in E. coli and crystallized using the hanging drop vapor diffusion method with sodium tartrate as the precipitant. The crystals belong to the tetragonal I4(1)22 space group, with unit cell parameters a=b=324.0, c=182.7 A. The diffraction data were collected up to a resolution of 3.0 A with a multi-wire area detector.

Crystallization↗

PubMed2003

Eye movements evoked by the selective stimulation of the utricular nerve in cats.

OBJECTIVE: Eye movements evoked by otolith organ are not well-investigated compare with canal related eye movements due to the technical difficulties. We try to solve this problem by means of our methods. METHODS: Eye movements evoked by selective utricular (UT) nerve stimulation were investigated using both electrooculography (EOG) and video recording in decerebrated cats in the presence or absence of anesthesia. Electrical stimulation was applied to the UT nerve through implanted acupuncture needles. RESULTS: In the absence of anesthesia and with stimulus intensities less than 2.6+/-0.7 x N(1)T, we found ipsilaterally directed horizontal eye movements in both eyes in one cat, abduction in the ipsilateral eye in two cats, and adduction in the contralateral eye in another cat. Other types of eye movements (e.g., supraduction or diagonal eye movements) were observed in both eyes of cats in the absence of anesthesia at a stimulus intensity of 12.2+/-7.6 x N(1)T, an intensity in which current spread to the adjacent nerve could not be ruled out. In the presence of anesthesia, UT nerve stimulation alone failed to evoke horizontal eye movements, but with an intensity 13.8+/-6.4 x N(1)T, supraduction or diagonal eye movements were evoked. UT nerve stimulation at 2-3 x N(1)T facilitated horizontal eye movements induced by ipsilateral abducens (AB) nucleus stimulation or contralateral horizontal canal nerve stimulation. CONCLUSION: This is the first report to our knowledge in which UT nerve-evoked horizontal eye movements are documented. These results confirm the known monosynaptic and disynaptic anatomical connections from utricular primary afferents to the ipsilateral AB nucleus neurons.

Abducens Nerve↗

PubMed2003

Compensatory changes in static and dynamic subjective visual vertical in patients following vestibular schwanoma surgery.

OBJECTIVE: Among patients with vestibular schwanoma (VS), vestibular function is nonhomogeneous, both before and after surgical removal of the VS. This paper reports investigations of neural changes, especially changes in the contribution of visual input to vestibular system integration, after VS surgery. METHODS: We examined 33 patients who underwent VS surgery via a middle fossa approach. Static and dynamic subjective visual vertical (SVV) was measured once after surgery and compared to those measured in control subjects. SVVs were assessed using a paradigm requiring the subject to manually adjust an image of a bar to the perceived vertical alignment. SVVs were measured when the background was stationary or rotating. RESULTS: In almost all patients, static SVV deviated toward the operated side. In VS subjects, the mean static SVV was 1.8+/-2.2 degrees; the amount of deviation in the dynamic SVV toward the operated side (11.7+/-8.3 degrees ) was significantly larger than that to the intact side (8.8+/-5.5 degrees ). In VS subjects, static SVV was correlated with dynamic SVV only in cases of bar adjustments toward the operated side (R=0.67, P<0.001), but not in cases of adjustments toward the intact, unoperated side. The axis of rotation was defined as the mean value of dynamic SVV for adjustments toward either side. There was only a weak correlation between the static SVV and the axis of rotation (R=0.31; P<0.05) in the control subjects. On the other hand, a more robust correlation between static SVV and axis of rotation was found (R=0.67, P<0.001) in VS subjects. There was no correlation between the static SVV and the deviation of dynamic SVV from static SVV for CCW and CW in control subjects. In contrast, there were significant correlations between static SVV and deviation of dynamic SVV from static SVV for adjustments made toward both operated (r=0.48, P<0.001) and intact sides (r=038, P<0.05). CONCLUSION: It is assumed that the amount of deviation in static SVV reflects the individual level of compensation. In addition, increased visual dependency evoked a symmetrical bias of the dynamic SVV from the measures at initial SVV assessment (i.e. static SVV or the center of tilt). As a result, we conclude that the contribution of visual inputs had changed after surgery, while at the same time, each patient used their static SVV as their reference point for orientation.

Adaptation, Physiological↗

PubMed2002

Gradual and reversible central vestibular reorganization in frog after selective labyrinthine nerve branch lesions.

Postlesional reorganization of vestibular afferent and commissural inputs onto second-order vestibular neurons was studied in the isolated brain after unilateral section of the N.VIII, of the ramus anterior (RA) of N.VIII, of the utricular (UT) or of the anterior vertical and horizontal canal nerves in combination. RA nerve section eliminated the inputs from utricular, anterior vertical and horizontal canal organs. In the first set of experiments we recorded field potentials on the operated side of the vestibular nuclei 2 months after RA nerve section. These responses were evoked by electrical stimulation of the RA nerve or of the posterior vertical canal nerve on the operated or on the intact side. The amplitudes of afferent field potentials evoked by stimulation of the spared posterior vertical canal nerve were increased. The amplitudes of afferent field potentials evoked by stimulation of the axotomized RA nerve remained unaltered. After N.VIII section the commissural, but not the afferent, field potentials increased significantly on the operated side following stimulation of N.VIII on the intact and on the operated side, respectively. After UT nerve section no change in commissural but an increase in the amplitude of afferent field potentials from each of the three intact canal nerves was observed on the operated side. In the context of earlier results these findings imply that second-order vestibular neurons, disfacilitated due to afferent nerve section, became receptive to additional, excitatory synaptic inputs, preferentially from intact vestibular nerve afferent fibers. The reduced excitation via afferent nerve inputs was thereby replaced by other afferent nerve inputs from spatially inadequate vestibular end-organs. The synaptic terminals of inactivated afferent nerve fibers were maintained and not repressed. The process of central reorganization after vestibular nerve lesion was activity related, the expansion of signals restricted to inputs from intact fibers, its extent graded and its onset delayed with respect to the onset of corresponding spinal changes and to the onset of postural recovery after the same type of nerve lesion. After the section of RA nerve or of an individual nerve branch the labyrinthine end-organs remained intact and were not removed as after unilateral labyrinthectomy (UL). Peripheral reinnervation of the end-organs was thus excluded after UL, but expected after one of the former types of lesion. Functional reinnervation of the utricular macula was mirrored behaviorally by the reappearance of severe postural deficits following a second RA nerve section. These lesion-induced postural deficits began to reappear if the repeated RA nerve section was delayed with respect to the first by about 3 months. We therefore studied postlesional reorganization in the brainstem 3 months after the first RA nerve section. Reinnervation of the utricular macula was accompanied by a rapid decline of the increased amplitudes of afferent and commissural vestibular field potentials towards control values, suggesting the reversibility of the lesion-induced central reorganization.

Afferent Pathways↗

PubMed2002

Three-dimensional analysis of nystagmus in benign paroxysmal positional vertigo. New insights into its pathophysiology.

Nystagmus is a rhythmical rotation of the eyeball. Its characteristics can be defined mathematically by the axis of rotation and the angular velocity around this axis. We analysed the axis of rotation for the nystagmus in benign paroxysmal positional vertigo (BPPV) to elucidate its pathophysiology. Thirteen patients with typical unilateral BPPV participated in the present study. The axis of rotation for the nystagmus was calculated from images recorded on digital videotape with an infrared CCD camera, using an algorithm that we developed. The patients' responsiveness to Semont's liberatory maneuver was also assessed.The results showed that patients could be assigned to one of two groups based on the rotation axis of the nystagmus. In one group of patients (n = 7; Group A), the axis of rotation was almost vertical to the plane containing the posterior semicircular canal (PSC) on the presumed affected side. In the other group of patients (n = 6; Group B), it was clustered around the naso-occipital axis. These results suggest that in the patients in Group A the responsible lesion is confined to the PSC, whereas the pathogenesis underlying the conditions in those in Group B is considered to be more complicated. This speculation was reinforced by the difference in responsiveness to Semont's liveratory maneuver. All of the patients in Group A showed remission of vertigo within 10 days (mean, 2.4 days) after onset of treatment using Semont's liberatory maneuver, whereas the patients in Group B required much longer periods of time for remission to occur (mean, 25.7 days). Our findings lead to the conclusion that by considering the spatial orientation of individual semicircular canals, in the patients in Group B the pathophysiology is not confined to the PSC, but most probably all three semicircular canals are involved.

Adult↗

PubMed2002

Dynamic and static subjective visual vertical with aging.

OBJECTIVE: Our vestibular function is gradually deteriorating during aging, although, its behavioral consequences are not easily recognized due to a substitution process by other sensory modalities as visual or proprioceptive inputs. METHODS: To reveal such a hidden substitution process by visual signals, the measurement of the static as well as the dynamic subjective visual vertical (SVV) was performed among 63 healthy subjects of different age. RESULTS: The static SVV was found to be stable among all subjects, whereas the shift of the dynamic SVV during rotation of a background scene gradually increased with age. CONCLUSION: This result indicates that the substitution process identified as a function of age in a perceptual test may have its counterpart in postural stabilizing reflex.

Adult↗

PubMed2002

Transgenic rice is a source of iron for iron-depleted rats.

Iron deficiency is one of the most prevalent nutrient deficiencies in the world. A sustainable solution to dietary iron deficiency may be achieved in part by increasing bioavailable iron in seeds used for foods such as rice. Because ferritin is used as a natural source of iron in the early development of humans, other animals and plants, the bioavailability of iron in rice seeds, provided in amounts equal to ferrous sulfate, and in transgenic rice with ferritin was tested in iron-deficient rats. A standard hemoglobin (Hb) repletion bioassay was used with rats made anemic followed by complete diets containing equivalent amounts of iron as FeSO(4) or one of three different bioengineered rice varieties (Kitaake and two transgenic derivatives with ferritin targeted to the seed, FK11 and FK22). Rice diets were as effective as the FeSO(4) diet in replenishing hematocrit, Hb concentration and liver iron concentrations. These data suggest that Mendelian and biotechnological approaches to manipulating ferritin expression of seed iron in rice may contribute to a sustainable solution to global problems of iron deficiency.

Anemia, Iron-Deficiency↗

PubMedDate not supplied

Phase contrast microscopy with modified Hansel's staining: mast cell identification and activity-related changes in cell membrane refractivity in allergic nasal smears.

BACKGROUND: A new technique called phase contrast microscopy with modified Hansel's staining (used with bright field microscopy) was developed to identify mast cells (MCs) and granulocytes (eosinophil/neutrophil/basophil [E/N/B]). METHODS: Nasal scratching smears from 618 patients with Japanese cedar pollinosis were examined using this new technique. RESULTS: This technique permitted accurate morphological identification. MCs can be discriminated from E/N/Bs. The surface of the cell membrane appeared as low refractile (lr), moderately refractile (mr), or high refractile (hr). This was caused by the light, which is not related to the phase difference, but rather originated from the difference in the refraction of the direct light. In specimens from the onset stage (i.e., 1-3 days after onset), lr-MC and mr/hr-E/N/B were dominant. In specimens from the early stage (i.e., 4-7 days after onset), lr-E/N/B significantly increased in number. CONCLUSION: The phospholipid bilayers of the cell membrane exhibit a phase transition after the onset, and phase refractivity of the cell membrane is closely related to the activity of the cell. This indicates that in the onset stage, MCs are already activated, whereas most of the E/N/Bs are not. In contrast, the latter cell types become activated subsequently in the early stage.

Adult↗